In devices capable of color output (e.g., computer monitors, projectors, printers, etc.), the color output depends upon the input signal. Thus, in an ideal device, if the input signal corresponds to a constant color, then the color output should be constant.
In practice, however, the color output is not simply a function of the input signal, but may also depend upon physical characteristics of the device as well (e.g., the distance that light has to travel to reach a target position on the display surface, physical characteristics of the display surface, angles of reflection, mechanical components of a print head or display structure, electromagnetic properties, etc). These physical characteristics can often result in a constant input signal being displayed differently in different regions of the display surface.
This phenomenon causes unintended distortions in the colors of images. For example, if a computer monitor is to have a solid blue background, it may set each pixel of the display to utilize the same color input. However, physical characteristics of the monitor may cause certain positions of the display surface to be presented in a lighter shade of blue, while other positions are presented in a darker shade. Moreover, the displayed shade of blue may exhibit a shift in hue or saturation. Therefore, a need exists to achieve color uniformity in color output devices.